\section{Radiation Hardening}
\label{sec:radiation}
In Table \ref{tab:radiation}, the ITER radiation doses are shown.
% Empieza la tabla
\begin{table} [htbp]
\centering
\begin{threeparttable}[b]
		\caption{Radiation doses in ITER \cite{ITEROrg.2004}.}
		\label{tab:radiation}
		\begin{tabularx}{8,8cm}{|X|c|c|c|}
			\hline
			&\multicolumn{3}{|c|}{\bfseries Inspection Type}\\
			\cline{2-4}
			&\bfseries Scheduled &\bfseries Unscheduled &\bfseries Maintenance\\
			\hline
			\bfseries Dose rate\tnote{*}& \multirow{2}{*}{1500} &
			\multirow{2}{*}{15000} & \multirow{2}{*}{300}\\

			\bfseries (Gy/hr) & & &\\
			\hline
			\bfseries \multirow{2}{*}{Duration} & 12 hr/week  & 12 hr/week
			& 60 hr/month\\
			& Over 7.5 years & Over 7.5 years& Over 32 months\\
			\hline
			\bfseries Total dose & \multirow{2}{*}{2.7} &
			\multirow{2}{*}{27} & \multirow{2}{*}{0.6}\\
			\bfseries gamma (MGy) & & &\\
			\hline
		\end{tabularx}
		\begin{tablenotes}
			\item[*] Estimated data
		\end{tablenotes}
\end{threeparttable}
\end{table}

Operation of electronics is a major problem when dealing with radiation
\cite{Perrot2004}. Despite multiplexing systems not being rated higher than
10kGy, some transistors are rated up to 10MGy. Therefore it can be expected to
design resistant components up to 10MGy with these transistors. The Radiation
Hardness Manual \cite{Campbell2007} also features few digital circuits (JK
flip-flops and bit to bit invertors) using discrete transistors that withstand
doses in the 10MGy range. For instance all the PAC \cite{Perrot2004} electronic
components are rated up to 10kGy integrated dose for full life time, under max
10Gy/hour dose rate.
Structural material must not be subject to degradation because of contamination.
Sensitive components like seals must be chosen knowingly of their radiation
resistance. Taking into account that the only barrier against radiation is mass
and that the dimensions requirements of the robot do not allow the use of such
as efficient barrier, every component intended to be used in the device should
therefore receive radiation testing to verify its operation at high doses.
%----------------
Several studies have been carried out listing doses for a wide range of
components to be used in vacuum vessel, from optical fibers to lubricants,
actuators and video cameras
\cite{VanUffelen2005,Leroux2006,Bock2008}.
These studies give high hopes on the fact that it would be possible to have
electronic designs compatible with the environment constraints.